Yeast Diversity and Persistence in Botrytis-Affected Wine Fermentations

AUTOR(ES)

Mills, David A.

FONTE

American Society for Microbiology

RESUMO

Culture-dependent and -independent methods were used to examine the yeast diversity present in botrytis-affected (“botrytized”) wine fermentations carried out at high (∼30°C) and ambient (∼20°C) temperatures. Fermentations at both temperatures possessed similar populations of Saccharomyces, Hanseniaspora, Pichia, Metschnikowia, Kluyveromyces, and Candida species. However, higher populations of non-Saccharomyces yeasts persisted in ambient-temperature fermentations, with Candida and, to a lesser extent, Kluyveromyces species remaining long after the fermentation was dominated by Saccharomyces. In general, denaturing gradient gel electrophoresis profiles of yeast ribosomal DNA or rRNA amplified from the fermentation samples correlated well with the plating data. The direct molecular methods also revealed a Hanseniaspora osmophila population not identified in the plating analysis. rRNA analysis also indicated a large population (>106 cells per ml) of a nonculturable Candida strain in the high-temperature fermentation. Monoculture analysis of the Candida isolate indicated an extreme fructophilic phenotype and correlated with an increased glucose/fructose ratio in fermentations containing higher populations of Candida. Analysis of wine fermentation microbial ecology by using both culture-dependent and -independent methods reveals the complexity of yeast interactions enriched during spontaneous fermentations.

Documentos Relacionados

• Molecular Monitoring of Wine Fermentations Conducted by Active Dry Yeast Strains
• Effect of Yeast Hulls on Stuck and Sluggish Wine Fermentations: Importance of the Lipid Component
• Occurrence of Killer Yeasts in Spontaneous Wine Fermentations from the Tuscany Region of Italy
• Sugar and Alcohol Stabilization of Yeast in Sweet Wine
• Polarographic Measurement of Dissolved Oxygen in Yeast Fermentations